Method of Monitoring the Status of a Wound

ABSTRACT

A system for determining a clinically relevant temperature differential between a predetermined area of interest on the body surface of a mammal and a control area on the body surface of said mammal, said system comprising: a visual and thermal image capturing device, said image capturing device comprising: a housing, a means for capturing a digital visual image within said housing; and a means for capturing a digital thermal image within said housing; a display apparatus, said display apparatus comprising means for showing said captured visual image and said captured thermal image; and a computing apparatus, said computing apparatus operatively connected to said image capturing device and to said display apparatus, said computing apparatus comprising: a means for selecting a control area on the surface of the skin; a means for determining an temperature of said control area; a means for selecting an area of clinical interest within said visual image; a means for calculating plane geometric features of said selected area of clinical interest; a means for overlaying said digital image onto said thermal image in a desired orientation on said display apparatus; and a means for applying a unique pixel value to a specific predetermined temperature range on said thermal image.

CROSS REFERENCE TO RELATED APPLICATIONS

The present continuation-in-part application claims priority toprovisional U.S. patent application No. 62/060,322, filed on Oct. 6,2014; pending non-provisional U.S. patent application Ser. No.13/439,177, filed on Apr. 4, 2012; and pending to non-provisional U.S.patent application Ser. No. 14/577,571, filed on Dec. 19, 2014.

BACKGROUND 1. Field of the Invention

The present invention relates generally to methods of using non-invasivetechnologies in medical care. More specifically, the present inventionrelates to novel thermal imaging methods and the use of the same in themedical field.

2. Description of the Prior Art

Over the last century, clinicians, which term includes herein certifiedand licensed medical doctors of all specialties, osteopathic doctors ofall specialties, podiatrists, dental doctors of all specialties,chiropractors, veterinarians of all specialties, nurses, and medicalimaging technicians, have become dependent on the use of medical devicesthat assist them in their delivery of patient-centered care. The commonfunction of these devices is to assist and not replace the clinicaljudgment of the clinician. This fulfills the dictum that best practiceis clinical judgment assisted by scientific data and information.

Entering into the era of computer science and sophisticated electronics,clinicians have the opportunity to be supported by data and informationin a statistically significant and timely fashion. These advancementshave allowed more extensive and useful collection of meaningful datathat can be acquired, analyzed, and applied in conjunction with theknowledge and expertise of the clinician.

Medical long-wave infrared (LIR) thermography has been known to bebeneficial in the evaluation of thermal heat intensity and gradiencyrelating to abnormalities of the skin and underlying tissue (SUT).Although this technology has expanded to other areas of medicalevaluation, the scope of this patent application is limited to the skinand underlying tissue abnormalities. These abnormalities include theformation of deep tissue injury (DTI) and subsequent necrosis caused bymechanical stress, infection, auto-immune condition, and vascular flowproblems. DTI caused by mechanical stress (pressure, shear andfrictional forces) can be separated into three categories. The firstcategory is a high magnitude/short duration mechanical stressrepresented by traumatic and surgical wound and/or areas of interest.The second category is low magnitude/long duration mechanical stressrepresented by pressure ulcer development, which is also a factor in thedevelopment of ischemic and neuropathic wound and/or areas of interests.The third category is a combination of categories one and tworepresented by pressure ulcer formation in the bariatric patient.

The pathophysiologic conditions that occur with DTI and subsequentnecrosis of the affected tissue are ischemia, cell distortion, impairedlymphatic drainage, impaired interstitial fluid flow, and reperfusioninjury: Category one is dominated by cell distortion and evendestruction. Category two is dominated by ischemia. Category three is acombination of cell distortion and ischemia.

Hypoxia causes aerobic metabolism to convert to anaerobic metabolism.This occurrence causes lactic acidosis followed by cell destruction,release of enzymes and lytic reactions. The release of these substancescauses additional cell injury and destruction, and initiation of theinflammatory response.

It is very important to recognize that ischemic-reperfusion injury isassociated with all of the above mechanical stress induced underlyingtissue injuries. This condition is caused by a hypoxia induced enzymaticchange and the respiratory burst associated with phagocytosis whenoxygen returns after an ischemic event. The result ofischemic-reperfusion injury is the formation of oxygen free radicals(hydroxyl, superoxide, and hydrogen peroxide) that cause damage tohealthy and already injured cells leading to extension of the originalinjury

Underlying tissue injury and subsequent necrosis can also be caused byvascular disorders. Hypoxia can be caused by an arterial occlusion or byvenous hypertension. Lymphatic flow or node obstruction can also createvascular induced injury by creating fibrous restriction to venousdrainage and subsequent cellular stasis in the capillary system. Thesedisorders are also accentuated by reperfusion injury and oxygen freeradical formation.

Infection of the skin (impetigo), underlying tissue (cellulitis), deeptissue (fasciitis), bone (osteomyelitis) and cartilage (chondritis)causes injury and necrosis of the affected tissue. Cells can be injuredor destroyed by the microorganism directly, by toxins released by themicroorganism and/or the subsequent immune and inflammatory response.These disorders arc also accentuated by reperfusion injury and oxygenfree radical formation.

Auto-immune morbidities of the skeletal joints (rheumatoid arthritis),skin and underlying tissue (tendonitis, myelitis, dermatitis) and bloodvessels (vasculitis) cause similar dysfunction and necrosis of thetissue being affected by the hypersensitivity reactions on the targetedcells and the subsequent inflammatory response. Again, these conditionsare accentuated by reperfusion and oxygen free radical formation.

The common event that addresses all of the above skin and underlyingtissue injuries is the inflammatory response. This response has twostages. The first stage is vascular and the second is cellular. Theinitial vascular response is vasoconstriction that will last a shorttime. The constriction causes decrease blood flow to the area of injury.The decrease in blood flow causes vascular “pooling” of blood (passivecongestion) in the proximal arterial vasculature in the region of injuryand intravascular cellular stasis occurs along with coagulation.

The second vascular response is extensive vasodilation of the bloodvessels in the area of necrosis. This dilation along with the “pooled”proximal blood causes increased blood flow with high perfusion pressureinto the area of injury. This high pressure flow can cause damage toendothelial cells. Leakage of plasma, protein, and intravascular cellscauses more cellular stasis in the capillaries (micro-thrombotic event)and hemorrhage into the area of injury. When the perivascular collagenis injured, intravascular and extravascular coagulation occurs. Therupture of the mast cells causes release of histamine that increases thevascular dilation and the size of the junctions between the endothelialcells. This is the beginning of the cellular phase. More serum and cells(mainly neutrophils) enter into the area of the mixture of injured anddestroyed cells by the mechanism of marginalization, emigration(diapedesis) and the chemotaxic recruitment (chemotaxic gradiency).Stalling of the inflammatory stage can cause the area of necrosis (ringof ischemia) to remain in the inflammatory stage long past theanticipated time of 2-4 days. This continuation of the inflammatorystage leads to delayed resolution of the ischemic necrotic event.

The proliferation stage starts before the inflammatory stage recedes. Inthis stage angiogenesis occurs along with formation of granulation andcollagen deposition. Contraction occurs, and peaks, at 5-15 days postinjury.

Re-epithelialization occurs by various processes depending on the depthof injury. Partial thickness wound and/or area of interests canresurface within a few days. Full thickness wound and/or area ofinterests need granulation tissue to form the base forre-epithelialization to occur. The full thickness wound and/or area ofinterest does not heal by regeneration due to the need for scar tissueto repair the wound and/or area of interest. The repaired scarred woundand/or area of interest has less vascularity and tensile strength ofnormal regional uninjured skin and underlying tissue. The final stage isremodeling. In this stage the collagen changes from type III to astronger type I and is rearranged into an organized tissue.

All stages of wound and/or area of interest healing require adequatevascularization to prevent ischemia, deliver nutrients, and removemetabolic waste. Following the vascular flow and metabolic activity of anecrotic area is currently monitored by patient assessment and clinicalfindings of swelling, pain, redness, increased temperature, and loss offunction.

Medical devices are now available to assist the clinician in definingthe presence, type, and status of the skin and underlying tissue injury.The LIR thermal and digital imaging device is a non-contact andnon-radiating device that can be utilized bedside. The combination ofimagers allows both visible and invisible radiation from the body to beevaluated. (See FIG. 1) This allows both the anatomical and physiologicstatus of the skin and underlying tissue to be evaluated for injuries ordisorders that are not yet clinically recognizable. By visualizing theIR thermal intensity, the clinician can evaluate the gradiency of thelong-wave radiation emitted from the body region being imaged. Theability to visualize the thermal gradiency allows the clinician toevaluate the metabolic activity and blood flow of the region beingimaged. The normal underlying tissue can be used as a control for thatspecific imaging procedure.

Having a real time control allows an area of interest (AOI) to berecognized. The AOI can be of greater intensity (hotter) or lessintensity (cooler) than the normal underlying tissue of that region ofthe body. The AOI can then be evaluated by the clinician for the degreeof metabolism, blood flow, necrosis, inflammation and the presence ofinfection by comparing the warmer or cooler thermal intensity of the AOIor wound and/or area of interest base and peri-AOI or wound and/or areaof interest area to the normal underlying tissue of the location beingimaged. Serial imaging also can assist the clinician in the ability torecognize improvement or regression of the AOI or wound and/or area ofinterest over time.

The use of an LIR thermal and digital visual imager can be a usefuladjunct tool for clinicians with appropriate training to be able torecognize physiologic and anatomical changes in an AOI before itpresents clinically and also the status of the AOI/wound and/or area ofinterest in a trending format. By combining the knowledge obtained fromthe images with a comprehensive assessment, skin and underlying tissueevaluation, and an AOI or wound and/or area of interest evaluation willassist the clinician in analyzing the etiology, improvement ordeterioration, and the presence of infection affecting the AOI or woundand/or area of interest.

The foundational scientific principles behind LIR thermographytechnology are energy, heat, temperature, and metabolism.

Energy is not a stand-alone concept. Energy can be passed from onesystem to another, and can change from one form to another, but cannever be lost. This is the First Law of Thermodynamics. Energy is anattribute of matter and electromagnetic radiation. It is observed and/ormeasured only indirectly through effects on matter that acquires, losesor possesses it and it comes in many forms such as mechanical, chemical,electrical, radiation (light), and thermal.

The present application focuses on thermal and chemical energy. Thermalenergy is the sum of all of the microscopic scale randomized kineticenergy within a body, which is mostly kinetic energy. Chemical energy isthe energy of electrons in the force field created by two or morenuclei; mostly potential energy.

Energy is transferred by the process of heat. Heat is a process in whichthermal energy enters or leaves a body as the result of a temperaturedifference. Heat is therefore the transfer of energy due to a differencein temperature; heat is a process and only exists when it is flowing.When there is a temperature difference between two objects or two areaswithin the same object, heat transfer occurs. Heat energy transfers fromthe warmer areas to the cooler areas until thermal equilibrium isreached. This is the Second Law of Thermodynamics. There are four modesof heat transfer: evaporation, radiation, conduction and convection.

Molecules are the workhorses and are both vehicles for storing andtransporting energy and the means of converting it from one form toanother. When the formation, breaking, or rearrangement of the chemicalbonds within the molecules is accompanied by the uptake or release ofenergy it is usually in the form of heat. Work is completely-convertibleto heat and defined as a transfer due to a difference in temperature,however work is the transfer of energy by any process other than heat.In other words, performance of work involves a transformation of energy.

Temperature measures the average randomized motion of molecules (kineticenergy) in a body. Temperature, is an intensive property by whichthermal energy manifests itself. It is measured by observing its effecton some temperature dependent variable on matter (i.e. ice/steam pointsof water). Scales are needed to express temperature numerically and aremarked off in uniform increments (degrees).

As a body loses or gains heat, its temperature changes in directproportion to the amount of thermal energy transferred from a hightemperature object to a lower temperature object. Skin temperature risesand falls with the temperature of the surroundings. This is thetemperature that is referred to in reference to the skins ability tolose heat its surroundings.

The temperature of the deep tissues of the body (core temperatures)remains constant (within ±1° F./±0.6° C.) unless the person develops afebrile illness. No single temperature can be considered normal.Temperature measurements on people who had no illness have shown a rangeof normal temperatures. The average core temperature is generallyconsidered to be between 98.0° F. and 98.6° F. measured orally or 99.0°F. and 99.6° F. measured rectally. The body can temporarily tolerate atemperature as high as 101° F. to 104° F. (38.6° C. to 40° C.) and aslow as 96° F. (35.5° C.) or lower.

Metabolism simply means all of the chemical reactions in all of thecells of the body. Metabolism creates thermal energy. The metabolic rateis expressed in terms to the rate of heat release during the chemicalreactions. Essentially all the energy expended by the body is eventuallyconverted into heat.

Since heat flows from hot to cold temperature and the body needs tomaintain a core temperature of 37.0° C.±0.75° C., the heat is conservedor dissipated to the surroundings. The core heat is moved to the bodysurface by blood flow. Decreased flow to the body surface helps conserveheat, while increased flow promotes dissipation. Conduction of the coreheat to the body surface is fast, but inadequate alone to maintain thecore temperature. Heat dissipation from the body surface (3 mmmicroclimate) also occurs due to the conduction, convection andevaporation.

Heat production is the principal by-product of metabolism. The rate ofheat production is called the metabolic rate of the body. The importantfactors that affect the metabolic rate are:

-   -   Basal Rate of Metabolism (ROM) of all cells of the body.    -   Extra ROM caused by muscle activity including shivering.    -   Extra ROM caused by the effect of thyroxine and other hormones        to a less extent (i.e.: growth hormone, testosterone).    -   Extra ROM caused by the effect of epinephrine, norepinephrine,        and sympathetic stimulation on the cells.    -   Extra ROM caused by increased chemical activity in the cells        themselves, especially when the cell temperature increases.

Most of the heat produced in the body is generated in the deep organs(liver, brain, heart and the skeletal muscles during exercise). The heatis then transferred to the skin where the heat is lost to the air andother structures. The rate that heat is lost is determined by how fastheat can be conducted from where it is produced in the body core to theskin.

The skin, underlying tissues and especially adipose tissue are the heatinsulators for the body. The adipose tissue is important since itconducts heat only 33% as effective as other tissue and specifically 52%as effective as muscle. Conduction rate of heat in human tissue is 18kcal/cm/m2 k. The skin and underlying tissue insulator system allows thecore temperature to be maintained yet allowing the temperature of theskin to approach the temperature of the surroundings.

Blood flows to the skin from the body core in the following manner.Blood vessels penetrate the adipose tissue and enter a vascular networkimmediately below the skin. This is where the venous plexus comes intoplay. The venous plexus is especially important because it is suppliedby inflow from the skin capillaries and in certain exposed areas of thebody (hands-feet-ears) by the highly muscular arterio-venousanastomosis. Blood flow can vary in the venous plexus from barely abovezero to 30% of the total cardiac output. There is an approximateeightfold increase in heat conductance between the fully vasoconstrictedstate and the fully vasodilated state. The skin is an effectivecontrolled heat radiator system and the controlled flow of blood to theskin is the body's most effective mechanism of heat transfer from thecore to the surface.

Heat exchange is based on the scientific principle that heat flows fromwarmer to cooler temperatures. Temperature is thought of as heatintensity of an object. The methods of heat exchange are: radiation(60%), loss of heat in the form of LIR waves (thermal energy),conduction to a solid object (3%), transfer of heat between objects indirect contact and loss of heat by conduction to air (15%) caused by thetransfer of heat, caused by the kinetic energy of molecular motion. Muchof this motion can be transferred to the air if it is cooler than thesurface. This process is self-limited unless the air moves away from thebody. If that happens, there is a loss of heat by convection. Convectionis caused by air currents. A small amount of convection always occursdue to warmer air rising. The process of convection is enhanced by anyprocess that moves air more rapidly across the body surface (forcedconvection). This includes fans, air flow beds and air warming blankets.

Convection can also be caused by a loss of heat by evaporation which isa necessary mechanism at very high air temperatures. Heat (thermalenergy) can be lost by radiation and conduction to the surroundings aslong as the skin is hotter than the surroundings. When the surroundingtemperature is higher than the skin temperature, the body gains heat byboth radiation and conduction. Under these hot surrounding conditionsthe only way the body can release heat is by evaporation. Evaporationoccurs when the water molecule absorbs enough heat to change to gas. Dueto the fact water molecules absorb a large amount of heat in order tochange into a gas, large amounts of body heat can be removed from thebody.

Insensible heat loss dissipates the body's heat and is not subject tobody temperature control (water loss through the lungs, mouth and skin).This accounts for 10% heat loss produced by the body's basal heatproduction. Sensible heat loss by evaporation occurs when the bodytemperature rises and sweating occurs. Sweating increases the amount ofwater to the skins surface for vaporization. Sensible heat loss canexceed insensible heat loss by 30 times. The sweating is caused byelectrical or excess heat stimulation of the anterior hypothalamus preoptic area.

The role of the hypothalamus (anterior pre-optic area) in the regulationof the body's temperatures occurs due to nervous feedback mechanismsthat determine when the body temperature is either too hot or too cold.

The role of temperature receptors in the skin and deep body tissuesrelate to cold and warm sensors in the skin. Cold sensors outnumber warmsensors 10 to 1. The deep tissue receptors occur mainly in the spinalcord, abdominal viscera and both in and around the great veins. The deepreceptors mainly detect cold rather than warmth. These receptorsfunction to prevent low body temperature. These receptors contribute tobody thermoregulation through the bilateral posterior hypothalamus area.This is where the signals from the pre-optic area and the skin and deeptissue sensors are combined to control the heat producing and heatconserving reactions of the body.

“Temperature Decreasing Mechanisms” include:

-   -   Vasodilation of all blood vessels, but with intense dilation of        skin blood vessels that can increase the rate of heat transfer        to the skin eight fold.    -   Sweating can remove 10 times the basal rate of body heat with an        additional increase in body temperature.    -   Decrease in heat production by inhibiting shivering and chemical        thermogenesis.

“Temperature Increasing Mechanisms” include:

-   -   Skin vasoconstriction throughout the body.    -   Increase in heat production by increasing metabolic activity,        which may include: Shivering (4 to 5 times increase) or Chemical        Thermogenesis i.e. burning fat, which may cause adults to have a        10-15% increase in temperature and infants 100% increase in        temperature.

LIR thermography evaluates the infra-red thermal intensity. Themicrobolometer is a 320×240 pixel array sensor that can acquire thelong-wave infrared wavelength (7-14 micron) (NOT near-infraredthermography) and convert the thermal intensity into electricalresistance. The resistance is measured and processed into digital valuesbetween 1-254. A digital value represents the long-wave infrared thermalintensity for each of the 76,800 pixels. A grayscale tone is thenassigned to the 1-254 thermal intensity digital values. This allows agrayscale image to be developed.

Using LIR thermography is a beneficial device to monitor metabolism andblood flow in a non-invasive test that can be performed bedside withminimal patient and ambient surrounding preparation. The ability toaccurately measure the LIR thermal intensity of the human body is madepossible because of the skins emissivity (0.98±is 0.01), which isindependent of pigmentation, absorptivity (0.98±0.01) reflectivity(0.02) and transmitability (0.000). The human skin mimics the“BlackBody” radiation concept. A perfect blackbody only exists in theoryand is an object that absorbs and remits all of its energy. Human skinis nearly a perfect blackbody as it has an emissivity of 0.98,regardless of actual skin color. These same properties allow temperaturedegrees to be assigned to the pixel digital value. This is accomplishedby calibration utilizing a “BlackBody” simulator and an algorithm toaccount for the above factors plus ambient temperatures. A multi-colorpalate can be developed by clustering pixel values. There are noindustry standards how this should be done so many color presentationsare being used by various manufacturers. The use of gray tone values isstandardized, consistent and reproducible. Black is usually consideredcold and white is usually considered hot by the industry.

An LIR camera has the ability to detect and display the LIR wavelengthin the electromagnetic spectrum. The basis for infrared imagingtechnology is that any object whose temperature is above 0° K radiatesinfrared energy. Even very cold objects radiate some infrared energy.Even though the object might be absorbing thermal energy to warm itself,it will still emit some infrared energy that is detectable by sensors.The amount of radiated energy is a function of the object's temperatureand its relative efficiency of thermal radiation, known as emissivity.

Emissivity is a measure of a surface's efficiency in transferringinfrared energy. It is the ratio of thermal energy emitted by a surfaceto the energy emitted by a perfect blackbody at the same temperature.

LIR thermography is a beneficial device to monitor metabolism, and bloodflow, and profusion of the skin and underlying tissue in a noninvasivetest that can be performed bedside with minimal patient and ambientsurrounding preparation. It uses the scientific principles of energy,heat, temperature and metabolism. Through measurement and interpretationof thermal energy, it produces images that will assist clinicians tomake a significant impact on wound and/or area of interest care(prevention, early intervention and treatment) through detection.

SUMMARY

Accurate and repeatable measurement of size is essential for documentingprogression or regression of the wound and/or area of interest. The longaccepted gold standard of length times width wound and/or area ofinterest measurement has been shown to have significant errors betweenwhen used to compare the results of one observer to another. The firstpart of the present invention provides a system and method of tracingthe wound and/or area of interest edge on a visual image to provideclinicians with both measurements of area and perimeter but the area andperimeter measurement have been shown to be more accurate than lengthtimes width with the perimeter measurement being the most accurate.Another aspect of the present invention discloses a system and methodfor using long wave infrared thermography to analyze physiologicalaspects such as perfusion and metabolic activity as measured by theeffect of a body surface temperature. In another aspect of the presentinvention there is disclosed a new combination of digital and long waveinfrared thermography cameras to simultaneously capture a visual andinfrared image of a wound and/or area of interest and surrounding bodysurface.

Once captured the visual image is used to document the appearance of awound and/or area of interest, trace the wound and/or area of interestsedge, and determine the area and perimeter of the wound and/or area ofinterest. The long wave infrared thermographic camera however is used toprovide insight into the physiological functions of a wound and/or areaof interest and surrounding body surface. The present invention providesmeans for a trace visual images wound and/or area of interest to beoverlaid onto the congruent thermal wound and/or area of interest shownby the long wave infrared thermographic camera.

The present invention uses long wave infrared thermography as atemperature measurement technique for the visualization andquantification of thermal energy emitted by the human body surface. Whenusing long wave infrared thermography, thermal energy is representedthrough a unique conversion of gray scale pixel values to temperaturevalues. The gray scale pixel value is a spectrum of absolute white toabsolute black where pixel value of one (absolute black) is usually (butnot necessarily) the coolest and a pixel value of 254 (absolute white)is usually (but not necessarily) the warmest.

Advantageously the system and methods of the present invention do notprovide absolute measurements of temperatures. Instead the system andmethod of the present invention allows clinicians to measure and recordthe temperature of a wound and/or area of interest area of interest andcompare that to known unaffected areas on the patient. Thus the effectsof extrinsic and intrinsic variables that affect absolute temperature ona given day and make absolute measurements unreliable for clinicalpurposes especially when taken across different days or by differentclinicians are avoided. Some of these intrinsic variables include thenormal cycle of thermal production, age, chromatic morbidities, bodyregion, medications, core temperature and others. Extrinsic variablesincluding ambient temperature, humidity, air convection, climateadaption of the tissue, configuration of the body surface, sub straighttemperature of the infrared core.

When assessing temperature data from multiple points in time, it isessential that the intrinsic and extrinsic variables described above areminimized. To accomplish this, selection of an unaffected area on a bodysurface can be used as a control relative to an affected area or likelyaffected area such as a wound and/or area of interest area of interest.Because the control is exposed to the same intrinsic and extrinsicvariables as the affected area, a comparison of the two makes themindependent of such variables. Since the temperature data can varybetween body regions, it is preferable that the selection of the controlarea occur on or near the same body surface of the area of interest. Ifunable to obtain the above, compare to same area on the contralateralside of the body or an available part of the body of the contralateralside is not available. This new reference area should be reproduciblefor a particular patent.

In combinations with other clinical information clinicians are providedwith relative quantitative data and relative qualitative data.Measurements of relative temperature differentia can allow clinicians toaccurately and reliably evaluate wound and/or area of interest bycomparing the same over time through ratio analyses, graphs, andalgorithms to unaffected areas thus eliminating the variables that mightaffect the accuracy of such measurements at a single point in time.

Thus, the present invention comprises, in one exemplary embodiment, asystem for determining a clinically relevant temperature differentialbetween a predetermined area of interest on the body surface of a mammaland a control area on the body surface of said mammal, said systemcomprising: a visual and thermal image capturing device, said imagecapturing device comprising: a housing, a means for capturing a digitalvisual image within said housing; and a means for capturing a digitalthermal image within said housing; a display apparatus, said displayapparatus comprising means for showing said captured visual image andsaid captured thermal image; and a computing apparatus, said computingapparatus operatively connected to said image capturing device and tosaid display apparatus, said computing apparatus comprising: a means forselecting a control area on the surface of the skin; a means fordetermining an temperature of said control area; a means for selectingan area of clinical interest within said visual image; a means forcalculating plane geometric features of said selected area of clinicalinterest; a means for overlaying said digital image onto said thermalimage in a desired orientation on said display apparatus; and a meansfor applying a unique pixel value to a specific predeterminedtemperature range on said thermal image.

In another exemplary embodiment, the present invention comprises amethod of contemporaneously comparing an average temperature ofpredetermined area of interest on the body surface of a mammal and acontrol area on the body surface of said mammal, said method comprisingthe steps of: capturing a physical image of a portion of the body of amammal; capturing a thermal image of said body portion; displaying saidphysical and said thermal image on a screen; selecting a control area onthe surface of the skin; determining an temperature of said controlarea; selecting an area of clinical interest within said visual image;calculating plane geometric features of said selected area of clinicalinterest; overlaying said digital image onto said thermal image in adesired orientation on said display apparatus; and applying a uniquepixel value to a specific predetermined temperature range on saidthermal image.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood more fully from the detaileddescription given hereinafter and from the accompanying drawings of thepreferred embodiment of the present invention, which, however, shouldnot be taken to limit the invention, but are for explanation andunderstanding only.

In the drawings:

FIG. 1A shows: A visual and thermal image capturing device according tothe present invention.

FIG. 1B shows: Left side view of the device open and closed of FIG. 1A.

FIG. 1C shows: Top view of the device open and closed of FIG. 1A.

FIG. 1D shows: front view of the device open and closed of FIG. 1A.

FIG. 1E shows: right side view of the device open and closed of FIG. 1A.

FIG. 1F shows: bottom side view of the device open and closed of FIG.1A.

FIG. 1G shows: back side view of the device open and closed of FIG. 1A.

FIG. 1H shows: Side by side thermal and visual images captured by thedevice of FIGS. 1A and 1B.

FIG. 2 shows: A computer display of a wound trace on a visual image ofthe body surface.

FIG. 3 shows: A computer display of a wound trace overlaid on a thermalimage of the body surface.

FIG. 4 shows: A computer display of a wound trace placed on a thermalimage of the body surface.

FIG. 5 shows: A non-relative “gray scale” for use with the presentinvention.

FIG. 6 shows: A non-relative “color scale for use with the presentinvention.

FIG. 7 shows: An exemplary “hot” thermal image for use with the presentinvention.

FIG. 8A shows: An exemplary “cold” thermal image for use with thepresent invention.

FIG. 8B shows: An exemplary “cold” thermal image for use with thepresent invention.

FIG. 9 shows: A “profile” line for use with the present invention.

FIG. 10A shows: A profile line plot showing body surface and underlyingtissue anomaly before and after resolution for use with the presentinvention.

FIG. 10B shows: A profile line plot showing body surface and underlyingtissue anomaly before and after resolution for use with the presentinvention.

FIG. 11 shows: A larger view of the profile line shown in FIG. 9.

FIG. 12 shows: A graphical representation of the data used to calculatethe center point of a traced area.

FIG. 13 shows: A graphical representation of orienting an unaffectedreference area based on head direction and the center point of thetraced area.

FIG. 14 shows: An alternative representation of orienting an unaffectedreference area based on head direction and the center point of thetraced area.

FIG. 15 shows: A graph and calculation for automatically calculating anunaffected reference area.

FIG. 16 shows: A photograph of a wound trace on a visual image of thebody surface.

FIG. 17 shows: A photograph of a wound trace placed on a thermal imageof the body surface.

FIG. 18 shows: A photograph of a graphical method of calculating thecenter point of a traced area.

FIG. 19 shows: A photograph of a graphical method before choosing properhead direction.

FIG. 20 shows: A photograph of the graphical method of FIG. 19 afterproper head direction has determined.

FIG. 21 shows: A photograph of an unaffected reference area displayed bythe present invention.

FIG. 22 shows: A photograph of a traced area, head direction, andunaffected reference area on a first day of study.

FIG. 23 shows: A photograph of the automatic unaffected reference areaof FIG. 22 on a second day of study; based on traced area, headdirection, and unaffected reference area from first day of study.

FIG. 24 shows: A photograph of the automatic unaffected reference areaof FIG. 22 on a third day of study; based on traced area, headdirection, and unaffected reference area from first day of study.

FIG. 25 shows: A non-relative “gray” scale as may be used with thepresent invention.

FIG. 26 shows: A non-relative “color” scale as may be used with thepresent invention.

FIG. 27 shows: A gray scale image before applying a non-relative colorscale.

FIG. 28 shows: A non-relative color scale based on the image in FIG. 27.

FIG. 29 shows: A relative color scale may be used with the presentinvention.

FIG. 30 shows: A relative color scale image comparing the area ofinterest to an unaffected reference area.

FIG. 31 shows: An exemplary graphical representation of a wound sitecomprising a wound base and periwound.

FIG. 32 shows: A computer display of wound trace on a visual image ofthe body surface.

FIG. 33 shows: A photograph of a wound trace overlaid on a thermal imageof the body surface.

FIG. 34 shows: A close up view of FIG. 33.

FIG. 35 shows: A photograph of a wound trace placed on a thermal imageas in FIG. 33.

FIG. 36 shows: A photograph of the display of FIG. 35 with anon-relative color scale.

FIG. 37 shows: A photograph of the wound of FIG. 33 with an unaffectedreference area selected.

FIG. 38 shows: A photograph of an overlaid wound trace and unaffectedreference area on a thermal image with a relative color scale.

FIG. 39 shows: A photograph of an overlaid wound trace, unaffectedreference area, and area of interest trace on a thermal image with arelative color scale.

FIG. 40 shows: A photograph of the relative color wound bend of FIG. 38combined with a non-relative gray scale image.

FIG. 41 shows: A photograph of the relative color periwound of FIG. 38combined with a non-relative gray scale image.

FIG. 42 shows: A photograph of the relative color wound site of FIG. 38combined with a non-relative gray scale image.

FIG. 43A shows: A plot of relative temperature histogram data from thewound bed, periwound, wound site, and unaffected reference area.

FIG. 43B shows: A plot of relative temperature histogram data from thewound bed, periwound, wound site, and unaffected reference area.

FIG. 43C shows: A plot of relative temperature histogram data from thewound bend, periwound, wound site, and unaffected reference area.

FIG. 43D shows: A plot of relative temperature histogram data from thewound bend, periwound, wound site, and unaffected reference area.

FIG. 44 shows: An exemplary algorithm for calculating the wound trace,overlaid wound trace, periwound trace, wound site trace, general (areaof interest) trace and unaffected reference area in the manner of thepresent invention.

FIG. 45 shows: A photograph of a wound trace in profile line.

FIG. 46 shows: A plot of the profile line of FIG. 45.

FIG. 47 shows: A plot of temperature gradiency of a wound bend.

FIG. 48 shows: A plot of the temperature gradiency of a periwound.

FIG. 49 shows: A plot of the temperature gradiency of the wound bedbased on the unaffected reference area.

FIG. 50 shows: A plot of the wound bed area.

FIG. 51 shows: A plot of the wound bed perimeter.

FIG. 52 shows: A plot of wound bed temperature gradiency compared to anunaffected area.

FIG. 53 shows: A plot periwound temperature gradiency compared to agradiency of an unaffected area.

FIG. 54 shows: A schematic of pixel values applied to a thermal image ofa wound.

FIG. 55A shows: Photographs comparing non-relative thermal images torelative thermal images.

FIG. 55B shows: Photographs comparing non-relative thermal images torelative thermal images.

FIG. 55C shows: Photographs comparing non-relative thermal images torelative thermal images.

FIG. 56 shows: Trace of visual wound edge.

FIG. 57 shows: Traced wound edge on thermal.

FIG. 58 shows: Center point of wound based on overlaid trace.

FIG. 59 shows: Head direction of wound selected based on visual orthermal image.

FIG. 60 shows: Head direction of wound selected based on visual orthermal image.

FIG. 61 shows: Reference area for software selected on thermal image.

FIG. 62 shows: Distance from vertex to reference area on first day.

FIG. 63 shows: Distance from vertex to reference area on second day.

FIG. 64 shows: Distance from vertex to reference area on third day.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention will be discussed hereinafter in detail in termsof the preferred embodiment according to the present invention withreference to the accompanying drawings. In the following description,numerous specific details are set forth in order to provide a thoroughunderstanding of the present invention. It will be obvious, however, tothose skilled in the art that the present invention may be practicedwithout these specific details. In other instance, well-known structuresare not shown in detail in order to avoid unnecessary obscuring of thepresent invention.

The following detailed description is merely exemplary in nature and isnot intended to limit the described embodiments or the application anduses of the described embodiments. As used herein, the word “exemplary”or “illustrative” means “serving as an example, instance, orillustration.” Any implementation described herein as “exemplary” or“illustrative” is not necessarily to be construed as preferred oradvantageous over other implementations.

All of the implementations described below are exemplary implementationsprovided to enable persons skilled in the art to make or use theembodiments of the disclosure and are not intended to limit the scope ofthe disclosure, which is defined by the claims. In the presentdescription, the terms “upper”, “lower”, “left”, “rear”, “right”,“front”, “vertical”, “horizontal”, and derivatives thereof shall relateto the invention as oriented in FIG. 1.

Furthermore, there is no intention to be bound by any expressed orimplied theory presented in the preceding technical field, background,brief summary or the following detailed description. It is also to beunderstood that the specific devices and processes illustrated in theattached drawings, and described in the following specification, aresimply exemplary embodiments of the inventive concepts defined in theappended claims. Hence, specific dimensions and other physicalcharacteristics relating to the embodiments disclosed herein are not tobe considered as limiting, unless the claims expressly state otherwise.

Accurate and repeatable measurement of size is essential for documentingprogression or regression of the wound and/or area of interest. The longaccepted standard of wound and/or area of interest measurement is tomultiply the length of the wound and/or area of interest by its width.However, this method has been shown to have significant errors when usedto compare the results of one observer to another. The present inventionprovides a system and method of tracing the wound and/or area ofinterest edge on a visual image to provide clinicians with bothmeasurements of wound and/or area of interest area and perimeter. Thepresent invention further comprises a system and method for using longwave infrared thermography to analyze physiological aspects such asperfusion and metabolic activity as measured by the effect of a bodysurface temperature. In another aspect of the present invention there isdisclosed a new combination of digital and long wave infraredthermography cameras to simultaneously capture a visual and infraredimage of a wound and/or area of interest and surrounding body surface.

Using the system and methods of the present invention, a visual image iscaptured and used to document the appearance of a wound and/or area ofinterest, trace the wound and/or area of interests edge, and determinethe area and perimeter of the wound and/or area of interest.Simultaneously, a long wave infrared thermographic camera is used toprovide insight into the physiological functions of a wound and/or areaof interest and surrounding body surface. The present invention thusincludes means for a trace around an area of interest on a visual imageof a wound and/or area of interest to be overlaid onto the congruentthermal wound and/or area of interest shown by the long wave infraredthermographic camera.

The present invention further comprises using long wave infraredthermography as a temperature measurement technique for thevisualization and quantification of thermal energy emitted by the humanbody surface. When using long wave infrared thermography, thermal energyis represented through a unique conversion of gray scale pixel values totemperature values. The gray scale pixel value is a spectrum of absolutewhite to absolute black where pixel value of one (absolute black) is thecoolest and a pixel value of 254 (absolute white) is the warmest. Sincethe imaging device of the present invention is calibrated to within arange of 22 to 42 degrees Celsius, it is able to detect temperaturedifferentials within 0.08 degrees Celsius.

Advantageously, the system and methods of the present invention do notprovide absolute measurements of temperatures. Instead, the system andmethod of the present invention allows clinicians to measure and recordthe temperature of a wound and/or area of interest area of interest andcompare that to known unaffected areas on the patient. Thus, the effectsof intrinsic and intrinsic variables that affect absolute temperature ona given day and make absolute measurements unreliable for clinicalpurposes especially when taken across different days or by differentclinicians are avoided. Some of these intrinsic variables include thenormal cycle of thermal production, age, chromatic morbidities, bodyregion, medications, core temperature and others. Extrinsic variablesincluding ambient temperature, humidity, air convection, climateadaption of the tissue, configuration of the body surface, sub straighttemperature of the infrared core.

When assessing temperature data from multiple points in time, it isessential that the intrinsic and extrinsic variables described above areminimized. To accomplish this, selection of an unaffected area on a bodysurface can be used as a control relative to an affected area or likelyaffected area such as a wound and/or area of interest area of interest.Because the control is exposed to the same intrinsic and extrinsicvariables as the affected area, a comparison of the two makes themindependent of such variables. Since the temperature data can varybetween body regions however it is important that the selection of thecontrol area occur on or near the same body surface of the area ofinterest.

In combinations with other clinical information, clinicians are providedwith relative quantitative data and relative qualitative data as shownin FIG. 55. Measurements of relative temperature differentia can allowclinicians to accurately and reliably evaluate wound and/or area ofinterest areas of interest by comparing the same over time through ratioanalyses, graphs, and algorithms to unaffected areas thus eliminatingthe variables that might affect the accuracy of such measurements at asingle point in time.

In the present invention, thermal images taken of the body surface areconstructed by passively reading emitted radiant energy formed by theunderlying tissue and the skin tissue by detecting wavelengths in thelong-wave infrared range (LIR) of 7-14 microns, and then in real timeconverting these values into pixels within a digital image. The valueassigned to the pixel indicates the thermal intensities of a particulararea of the skin when imaged. Thermal images are presented in digital8-bit grayscale with pixel values ranging from 0-254. Generally, theunaffected skin thermal intensity will be a uniform gray color within arange of +/−3 to 6 pixel values, which is equal to 0.25 to 0.5 degreescentigrade. Abnormally hot areas of the skin will be represented bypatches of increasingly white pixels, while abnormally cold areas willbe represented by increasingly dark patches of pixels.

These same techniques work with images of varying color resolutions.

These images are preferably stored in a data bank along with informationabout the data that can be retrieved by a clinician for future reviewand analysis.

The use of LIR (7-14 microns) imaging along with visual digital imagingallows both physiologic (long-wave infrared and visual) and anatomicassessment of skin and underlying tissue abnormalities and or existingopen wound and/or area of interests. The gradiency of the thermalintensity, not the absolute amount of intensity, is the importantcomponent of the long-wave thermal image analysis that will allow theclinician to evaluate pathophysiologic events. This capability isbeneficial to the clinician in the prevention, early intervention andtreatment assessments of a developing existing condition caused by, butnot exclusively, wound and/or area of interests, infection, trauma,ischemic events and autoimmune activity.

As stated previously herein, utilizing absolute temperature values (P,C0, and Kelvin) as the numerical values of LIR thermal heat intensity iscomplicated due to the need to have a controlled environment. This isrequired since the value of the absolute temperature scales is affectedby ambient temperature, convection of air, and humidity. These variableswould need to be measured and documented continuously if temperaturevalues were used. Also the emissivity, absorptivity, reflexivity andtransmitability of the skin and underlying tissue can be affected byskin moisture, scabbing, slough and/or eschar formation in an open woundand/or area of interest.

The thermal imager of the present invention utilizes raw data capturedby a microbolometer. This data is utilized in determining pixel valuesrelating to the intensity of the thermal energy from the long-waveinfrared electromagnetic radiation spectrum being emitted by the humanbody. The pixel gradient intensities are represented for visualizationby the grayscale presentation.

The pixel values in the grayscale thermal images also vary with thevarying conditions mentioned above and hence the algorithms proposed inthis application use the average pixel value of the unaffected skinregion for that patient on the day the image was taken as a referencepoint for all the calculations.

There is a difference in the LIR thermal intensity regions of the humanbody. LIR images have a defined pixel intensity range that is based onthe specific usage of an LIR image. In the arena of skin and underlyingtissue LIR thermal gradiency, the range is within homeostasisrequirements to sustain life. The visualization of pixel intensities isaccomplished by the use of a standardized 8-bit grayscale. Black definescold, gray tones define cool and/or warm and white defines hot. When theimager is used for capturing extremely hot or extremely cold regionsthat fall outside the thermal range of the imager, the pixel valuesreach the saturation point, and it becomes extremely difficult for thehuman eye to differentiate variations in the pixel values.

Visual and thermal imagers used in the imaging apparatus of the presentinvention don't have the exact same field of view. Hence, the digitalvisual and thermal images cannot be overlaid automatically. To help theuser with positioning the overlay image, the present invention comprisesimage alignment line feature by which a user can draw a line tracing theedges of an area of interest of a body part seen in a visual image. Atransparent image is created showing the area traced on the visual imagewhich is then overlaid on top of a thermal image. When creating thetransparent overlay image, the lines along with the trace will beincluded. Since the edges of the human body are clearly distinguishablein a thermal image, having an alignment line, described herein below,along with the trace, provides visual aid in deciding the properpositioning of the overlay.

Once the trace has been placed around the area of interest on the visualimage, for each coordinate along the trace, by adding the X and Y shift,the corresponding X and Y coordinates on the thermal image can beobtained. A transparent image is created and a trace is drawn using thenew X and Y coordinate and is overlaid on top of the thermal image asshown in the figure below, allowing the user to position it if neededbefore dropping the trace on the digital image.

When the user confirms the position where the trace needs to be droppedin the thermal image, the overlay image is removed and the trace isplaced on the thermal image itself as shown in FIG. 3.

Long wave infrared thermography captures thermal images that can provideinsight into the physiological functions of the wound and/or area ofinterest and the surrounding body surface. They provide more in-depthinformation than an image captured using a regular digital camera. Themethod of the present invention comprises software means that allow theuser to trace an area of interest and obtain several measurementsincluding for example temperature gradiency within the wound and/or areaof interest which is helpful in tracking the progression or regressionof the area of interest.

Thus, the system and methods of the present invention allow a user toanalyze a pair of thermal and visual images to obtain an in-depthunderstanding of the status of an area of interest on a patient. Usingthe present system and methods a trace is drawn around an area ofinterest on a visual image representing. The area and perimeter for thetraced area are calculated and displayed as results. The traced area onthe visual image is then overlaid on a thermal image.

The thermal core, however, of a camera according to the presentinvention is likely to produce an image with barrel distortion. Inbarrel distortion, image magnification decreases with distance from theoptical axis. The apparent effect is that of an image which has beenmorphed around a sphere or a barrel. In order to correct for barreldistortion, several different methods may be used. However in thepresent invention, it's preferable to use the lens distort algorithmavailable in MATLAB. The algorithm takes as input the original distortedimage as well as additional parameters and generates as output a barreldistortion corrected image. The method of accomplishing this is shown inAppendix 1. Those of skill in the art will appreciate that the colorscale has a degree of predetermined “grouping” to enhance visual,clarity.

The barrel distortion corrected image is then adjusted for Keystonecorrection. In order to make sure that both cameras are pointing at thesame field of view, the thermal camera is installed at an angle whichproduces a Keystone effect on the images. The Keystone effect algorithmdeveloped in MATLAB takes the input image that needs to be corrected andthe amount of blank space and generates the corrected images as output.

Thus, when the images are opened, the system of the present inventionincorporates software means for correcting the images for barrel (andKeystone) distortion before the images are displayed on a screen for theuser. The distortion correction software is applied each time the imagesare opened, but the original image data is never altered. In thepreferred embodiment of the present invention, the only data stored inthe database is the original images. The parameters used for thedistortion correction are specific to each calibrated image capturedevice.

The image capture device of the present invention may furtherincorporates means for live video stream image capture from the thermalcamera. Visual and thermal captured images may be displayed and stored(in grey scale, another color scale, or in a specific pixel value scale)simultaneously. The image is captured or stored in a database in theiroriginal format, i.e. without distortion correction. Distortioncorrection is not applied until the image is uploaded and pulled fromthe database for review.

A trace has been drawn around an area of interest on the visual imagefor later study. For each coordinate along the trace, by adding the Xand Y shift, the corresponding X and Y coordinates on the thermal imagecan be obtained. A transparent image is created, and a trace is drawnusing the new X and Y coordinates and is overlaid on top of the thermalimage allowing the user to position it if needed before dropping thetrace onto the thermal image. The user confirms the position where thetrace needs to be dropped on the thermal image overlay. The overlayimage is then removed and the trace is drawn on the thermal imageitself.

To help the user with positioning the overlay image, an image alignmentline feature is incorporated into the system of the present invention toallow the user to draw a line tracing the edges of the body part on thevisual image. When creating the transparent overlay image, the linealong with the trace is included. Since the edges of the human body areclearly distinguishable in a thermal image, having an alignment linealong with a trace provides visual aid in deciding the properpositioning of the overlay. Once a trace has been drawn on the thermalimage an unaffected reference point can be selected. To help with theprocess of selecting an unaffected reference point, a gray scale or ironscale thermal mosaic is applied to the thermal image. Grey scales (orother color scales, such as “iron”) are used for “unbundled” raw data.“Bundled” data uses a single reference point rather than a referencearea.

An area of interest needs to be traced before the unaffected referencepoint can be selected. The mean or average pixel value of the tracedarea is used as a reference. For the thermal images captured using thedevices disclosed in the present invention, a pixel value difference ofpreferably about 12 represents a one degree Celsius change intemperature. All of the pixels whose pixel values fall within the rangeof a mean of plus or minus six are considered suitable to be selected asa reference point. A different color is used for representing eachdegree change in temperature. White is generally used to represent hot,and black generally represents cold in the preferred embodiment.However, those with skill in the art will appreciate that any colors maybe chosen. Similarly for the R G B scale it is preferred to use red torepresent hot and green or blue to represent pixels that are colder thanthe reference area.

To select an unaffected reference point a user of the system of thepresent invention should check whether a thermal trace exists. If yes,check to see whether pixels fall inside the trace and use the pixelvalues of all those pixels to calculate the average pixel value, decideon the color codes that represent each temperature interval, for example15 different shades are chosen for the color scale, then use the basecolor that falls within the color scale to highlight all pixels within apixel mean value of between plus and minus six. Appendix 2 shows thelogic used to color the rest of the pixels.

After reviewing the images by drawing traces and obtaining measurementsout of these traces, a particular session with regard to a particularpatient may be saved. The system of the present invention can generatevisual or graphical or tabular results based on the images obtained andthe calculations made. FIGS. 32-43 show various representations of thesteps of the methods described above.

FIG. 44 shows an exemplary logic model for the visual overlay trace andthe wound and/or area of interest sight trace aspects of the presentinvention. In FIG. 46 shows a profile line plot according to the methodof the present invention. FIG. 45 shows a visual representation on apatient of the profile line plot shown in FIG. 46.

FIGS. 47 through 53 show various graphical representations of thecalculations that can be performed by the system in methods of thepresent invention.

The periwound is defined as the skin and all underlying tissuesurrounding contiguously with the area that is recognized as the woundand/or area of interest base. Abnormalities of this tissue can beclinically or non-clinically recognizable. The periwound should beconsidered a deep tissue injury prone area. Accordingly, the periwoundis an ideal area of interest for a trace on the visual image of a woundand/or area of interest.

The periwound is the tissue surrounding the wound and/or area ofinterest itself. This tissue provides an access corridor for blood, etc.to the wound and/or area of interest, for healing and progress.Complications to this ideal function come because periwound tissue canbe adversely affected by infection prolonged inflammation; poor bloodsupply; poor metabolic activity. It is important to clean the area ofthe wound and/or area of interest and monitor the status of the woundand/or area of interest and periwound including the skin and underlyingtissue. Even using the infrared thermographic images sometimes it isdifficult to trace the edges of a periwound as the periwound region doesnot have an abrupt change in thermal intensity due to infrared radiationversus visual. Instead, it slowly fades into the unaffected portion ofthe skin.

To assist clinicians in choosing the periwound accurately, the followingtechnique was developed:

-   -   1. Trace the area of interest or the visual image;    -   2. Overlay the trace from visual image onto the thermal image.        The overlaid trace can now be treated as the wound and/or area        of interest base;    -   3. Allow the user to specify the distance in centimeters,        generally 1 to 5 centimeters, between the wound and/or area of        interest base edge and the periwound edge;    -   4. Using the coordinates of the wound and/or area of interest        base and the distance information a new set of coordinates can        be calculated that represent the corners of the periwound.

To highlight the abnormal area of interest in a visual image:

-   -   1. Start tracing the area of interest by clicking on the image;        see the X and Y coordinates of the click points.    -   2. Use the mouse, or other input device to draw lines connecting        the adjacent points on the computer screen.    -   3. When the user double clicks the mouse join the last point of        the first point which finishes up the trace.    -   4. Using each click point as a coordinate determine which pixels        fall inside the polygon area representing the trace. The trace        now represents the wound and/or area of interest base region as        shown on the figure below.

Once the wound and/or area of interest base area has been traced, theuser is given an option to provide the distance between the wound and/orarea of interest base and the periwound regions. The user can specifythe distance in centimeters or any other convenient set of measuringunits. By knowing the distance at which the image was captured, we canconvert the distance in centimeters to distance in pixels. For example,we know that for a thermal image captured at 18 inches, there would beapproximately 40 pixels in an inch. So, if the user says the distancebetween the periwound base and the periwound traces is 1 centimeter, wecan calculate the corresponding number of pixels between the two traces.

The wound and/or area of interest base can be considered as a polygonwhere each coordinate corresponds to a corner. The new coordinates ofthe periwound can be calculated by offsetting the polygon for a distanceequal to the distance (in pixels) between the two traces. The ClipperLibrary was used for performing polygon offsetting. This library isbased on Vatti's clipping algorithm. FIG. 4 shows the periwound traceobtained by offsetting the wound and/or area of interest base polygon by1 centimeter in all directions.

Since the polygon is offset by the same amount in all directions, thereare chances that a portion of the periwound trace may fall outside thedesired area (for example the trace may coincide with the background orother portions of the body that do not comprise the periwound. As a workaround for this problem the user can either manually resize theperiwound trace by altering the position of one or more of thecoordinates, or choose to exclude a certain portion of the trace thatfalls outside the desired area.

Wound and/or area of interest base and periwound together are consideredas the wound and/or area of interest sight. The status of these tracescan be monitored on a daily basis in comparison to previous measurementsto assess whether the wound and/or area of interest is getting better orgetting worse.

The periwound is defined as the area of skin surrounding a wound and/orarea of interest. The periwound can be traced on the thermal imageproduced by the systems and methods of the present invention thenoverlaid on the visual image. The area and perimeter of the periwoundcan then be calculated relative to the visual image.

The system checks to ensure that the periwound trace does not overlap orfall outside the trace representing the base wound and/or area ofinterest. Periwound calculations include only the pixels that fallinside the outer thermal trace but not inside the wound and/or area ofinterest bed trace. The combination of the two is the wound site, asshown in FIG. 31.

A control unaffected area is chosen which allows for a true relativetemperature comparison between an unaffected area and areas of interest.Relative temperature gradients above about 1.5 to 2 degrees Celsius areknown to indicate significant physiological aberrations. Possible causesfor these aberrations may include hyperthermia caused by inflammation orinfection or hypothermia caused by poor perfusion and/or tissuenecrosis. The present invention allows means to display the visual andthermographic recorded data concurrently in a quantitative and organizedsequential format while storing the objective data for future reference.

Combining the above technique with suggested usage of unaffected skinand underlying tissue in the proximity of an abnormality of askin/underlying tissue location as a real time control helps to minimizethe variability and time consuming requirements in utilizing temperaturescales.

Choosing a controlled unaffected reference area (“CUA”) allows for aminimization of intrinsic and extrinsic variables for the accuratedetermination of the relative temperature gradiency between the woundand/or area of interest base, periwound, or entire wound and/or area ofinterest sight in reference to the CUA. Relative temperature gradientsgreater than 0.5 degrees Celsius are known to indicate significantphysiological aberrations. Possible causes for hyperthermia includeinflammation, infection. Possible causes for hypothermia include poorperfusion, tissue necrosis, poor metabolic activity; inflammation. Usingthe systems and methods of the present invention visual and thermalrecorded data are displayed in human readable form in a quantitative andorganized sequential format. This thermal data allows for the objectiveassessment of relative parodies and disparities between the wound and/orarea of interest base, periwound, and entire wound and/or area ofinterest sight. This data, combined with other information provided bythe systems and methods of the present invention allows a clinician tosave and record quantitative measurements from both an anatomical andphysiological perspective that may otherwise go unseen.

As stated previously, an unaffective reference area needs to be chosensuch that the temperature variation (“gradiency”) across the area isless than 1.5 degrees Celsius. In order to aid with the selection ofreference area, features like a “profile line” and “color mosaic”provided in the software can be used.

The portion of the plot shown in FIG. 10 where the various intemperature is less than 1.5 degrees Celsius represent the suitableposition for selecting the unaffected reference area. The plot is userinteractive, so the user can click on the chart to highlight the pointon the image and vice versa.

A profile line is another tool provided by the systems and methods ofthe present invention that can be used to aid the user in selecting theunaffected reference point. Profile line plots show the variation in thepixel values across the line drawn at the top of the wound and/or areaof interest. Since the thermal intensity is directly related to the grayscale pixel values in an image, these plots can be used to monitor howthe thermal intensity is varying across the areas of interest.

Profile lines can be plotted by simply drawing a line across an area ofinterest. FIG. 9 shows an example of the profile line generated bydrawing a line starting from the center of the wound and/or area ofinterest base to a point that represents unaffected skin. As seen in theplot, there is a huge drop in the pixel value/thermal intensity acrossthe wound and/or area of interest base region and the value startsincreasing as the line is moving away from the wound and/or area ofinterest base and entering the areas with normal skin tissue.

FIG. 11 shows an unaffected reference area chosen using the profile lineplot. The area of interest can be traced as seen on the visual image andthen overlaid onto the thermal image. The results of the wound and/orarea of interest trace along with the information about head directionand unaffected reference area can then be used to predict the suitableposition for placing the reference point on the images captured atfuture times.

Automating the process of selecting a reference point based on theinformation provided makes the reference point selection more consistentand eliminates variation between users evaluating patients on differentdates. An algorithm used in the present invention for selecting areference point comprises of the following steps:

-   -   1. Selecting a direction of the head on a visual image;    -   2. Overlaying an external wound and/or area of interest trace        drawn on the visual image onto a thermal image or performing a        thermal wound and/or area of interest trace on the thermal        image;    -   3. And manually selecting a reference area on the thermal image.

Referring now to FIG. 12 there is shown a visual representation usefulin performing the calculations for selecting a reference point. Themethod of selecting a reference point includes calculating the distancebetween the center point of the external wound and/or area of interesttrace and the manually selected reference area. Since the wound and/orarea of interest trace is a polygon, to find the center of the polygonone must first find the minimum and maximum x coordinates along thehorizontal axis and the minimum and maximum y values along the verticalaxis. The distance between the center of the wound and/or area ofinterest trace polygon (x1, y1) and the center of the reference area(x2, y2, as shown in FIG. 12, can be calculated using a standarddistance formula where the distance equals the square root of (x2−x1)squared plus (y2−y1) squared. Next the angle formed between the selectedhead direction relative to the line joining the center point of theoverlaid external wound and/or area of interest trace from the thermalimage to the manually selected reference area is calculated. Withreference to FIG. 13, in order to calculate angle B, angles H and A needto be calculated. H is the head direction angle, and A is the angle madeby the line joining the center of the wound and/or area of interesttrace and the center of the reference point which can be calculated asfollows: If x1, y1 represent to the center of the wound and/or area ofinterest trace and x2, y2 represent to the center of the referencepoint, then the slope of the line can be calculated using traditionalgeometry as the slope equals y2−y1 divided by x2−x1. Since the slope canalso be defined as tangent of angle A, angle A can be calculated as Aequals tan superscript negative one times slope. Once angles H and A areknown, angle B can be calculated as B=A−H.

Thus in setting an automated reference area the user must set the headdirection on the visual image; overlay the external wound and/or area ofinterest trace and place it onto the thermal image or perform a thermalwound and/or area of interest trace on the thermal image; identify theautomated reference area feature then confirm the system determinedautomated reference area or manually place the same.

Based on user's current selection of head direction and the center pointof the overlaid external wound and/or area of interest trace from thethermal image, the system of the present invention approximates thelocation of prior reference areas as shown in FIG. 14.

Again, as shown in FIG. 14, if “H_(new)” is a new head direction anglefor the current session, based on the information from previous sessionsthe system of the present invention can determine the relative anglebetween the head direction line and a line joining the center of thewound and/or area of interest trace to the center of the reference point(B). Using the following formula: Theta=H_(new)+B, thereby giving theangle of the x axis.

For the imaginary line joining the center of the wound and/or area ofinterest trace to the center of the automated reference point, we knowthe starting point of the line which would be the coordinates of thecenter of the wound and/or area of interest trace, the angle made by theline along the x axis (Theta) and the length of the line, which is equalto the distance between the center of the wound and/or area of interesttrace and the center of the pre-selected reference point. Using thisinformation, the end point, the coordinates of the automated referencepoint, can be calculated as shown in FIG. 15.

User of the present invention is preferably given an option to eitheruse the automated reference area selection or to manually select a newarea. If the user chooses to use a manual selection instead, that manualselection now becomes the baseline. The user does not have to use theautomated reference area. The user could perform a manual selection eachtime the system and methods of the present invention are used.

FIGS. 16 through 24 herein display the various steps described in theprevious paragraphs for determining an automated reference area.

“Profile lines” can also be drawn to help with the selection of anunaffected reference point. Profile lines are freeform lines drawnacross the image. The profile line plots display the variation intemperature along the line. If the line is flat, it indicates thetemperature gradiency variation is very low and it is a suitablelocation for selecting the unaffected reference point. The user canclick on the plot and the corresponding location on the image ishighlighted by the system of the present invention. A user can thenplace the unaffected reference point in that location or choose adifferent one if the user so desires.

Even though the thermal images provide more in-depth definition of areaof interest than the digital image, it becomes harder to differentiatebetween small variations in temperature as it is difficult todifferentiate between shades of gray. The entire thermal image is madeup of 254 different shades of gray as shown in FIG. 5.

To make visual differences between temperature variations greater themethod of the present invention includes incorporating a unique colorfor each pixel value to generate a custom color bar as shown in FIG. 6.The custom color bar shown in FIG. 6 was developed using MATLAB'S colorbar editor.

To apply the custom color bar to the gray scale thermal image, thepresent invention incorporates the following algorithm:

-   -   1. Generate a matrix that holds the R, G, and B values of 254        different colors representing pixel values ranging from 1 to        254;    -   2. Obtaining the pixel value for each pixel in the image;    -   3. Finding the corresponding color for that pixel value;    -   4. Setting the pixel value for that pixel to the new color;    -   5. Applying the new color scale to the entire image;    -   6. Displaying the new image blended with the new color scale.

Unmanaged code can be used to make the above-explained process faster.FIGS. 7 and 8 below show the thermal images before and after applyingthe blended custom color scale described above.

By looking at either the original gray scale thermal image or the imagewith the color scale, unaffected reference area tissue can be selectedat a location that represent unaffected skin with less temperaturevariation.

As the wound and/or area of interest starts healing, the differencesbetween the pixel value for the unaffected tissue and the pixel valuefrom the wound and/or area of interest base starts decreasing and hencethe drop scene in the graph of FIG. 10. The decrease in temperatureshown in FIG. 10 indicates that a wound and/or area of interest ishealing and is starting to get closer to the unaffected skin tissue.

If the drop in the pixel value starts increasing, when plots aregenerated for images taken on a timely basis, then it is an indicationthat the wound and/or area of interest is deteriorating and theclinician needs to turn to strategies to facilitate wound and/or area ofinterest healing.

The thermal mosaic is the colored representation of a gray scale thermalimage. It shows the variation in pixel values using different colors.Even though thermal images provide more in-depth definition of area ofinterest than the digital image, it becomes harder to differentiatebetween small variations in temperature as it is difficult todifferentiate between shades of gray. The entire thermal image is madeup of 254 different shades of gray as shown in FIG. 25.

However to make the visual representation of the thermal image clearer,the present invention also provides for a custom color representation ofthe thermal image. To accomplish this each gray scale pixel value isassigned a specific pixel value using the MATLAB color bar editor asshown in FIG. 26.

To apply the custom color bar FIG. 26 to a gray scale thermal image thefollowing steps are performed:

-   -   1. Generating a matrix is that holds the R, G, and B values of        254 different colors representing the pixel values ranging from        1 to 254;    -   2. For each pixel in the image obtaining the pixel value;    -   3. Finding the corresponding color for each pixel and setting        the pixel value for that pixel to the new color;    -   4. Looping the image to apply the new color scale; and    -   5. Displaying the new image with the blended color scale.

FIGS. 27 and 28 show before and after images respectively for theblended color scale.

Using the original gray scale image or the image with the custom colorscale applied, an unaffective reference area can be chosen which can beused for tracking the progression or regression of an area of interest.

Once the reference area has been chosen, another custom color scaleoption can be provided where the mean pixel value of an unaffectivereference area is used as a reference and is represented in aparticularly desirable color. For example green. Using the new colorscale all the pixels in the image can be viewed relative to the selectedunaffected reference area. If an area of interest is warmer thanreference it will be assigned a color closer to the warmer end of thecolor scale and vice versa. FIG. 29 shows a new custom color scale thattakes unaffected reference area into consideration.

A method for applying a custom color bar to the gray scale thermal imagecomprises choosing an unaffected reference area such as the temperaturevariation within the area is less than 1.5 degrees Celsius, finding theaverage of all the pixel values that fall within the unaffectedreference area called the reference mean; generating a matrix that holdsthe R, G, and B values for the new custom colors; assigning each pixelin the image a pixel value; and calculating the difference between thecurrent pixel value and the reference mean. Using the formula differencein pixel value equals current pixel value minus reference mean. Findingthe R G B, color that corresponds to the difference in pixel value andsetting the pixel value for the pixel to the new color; looping thewhole image to apply the new color scale; and displaying the resultingimage with the blended color scale.

As shown in FIG. 30, all the portions of the image that have atemperature equal to the unaffected reference area are presented withthe same color in this case green. Using the above color scale as areference, and by comparing the color of an area of interest with anunaffected reference area, a clinician can get a clear understanding ofhow much cooler or warmer an area of interest is with respect to thereference area.

By monitoring the images on a scheduled basis and choosing a referencepoint consistently between the images a clinician is able to see apattern in which the temperatures across the area of interest arechanging. By monitoring changes in colors over time a clinician is ableto visually to interpret whether the wound and/or area of interest isgetting better or worse.

Thermal mosaic is the colored representation of the thermal image. Itshows the variation in pixel values using different colors. Gray scalecolors are used for the thermal mosaic before the unaffected referencepoint is selected, an R G B color scale is used after the selection ismade.

Once a reference point or reference area is selected, the color mosaiccan be turned on for the whole image and use that as a visual aid fordrawing the periwound trace. In order to generate the color mosaic, themean or average pixel value of the unaffected reference point or meanpixal value of the unaffected reference area is used as the mean in thealgorithm for generating a thermal mosaic. Since the reference point isjust one pixel, there is only one pixel value. If each time a userengages the system a different reference point is selected needlessvariation will be introduced. Since just one pixel is used as a pixelvalue, a reference mean is used instead to generate the color mosaicusing the methods disclosed in Appendix 3 attached hereto.

The thermal mosaic can be turned on or off for each trace separately.Using this information, clinicians can calculate using this system thedifference in thermal intensity within the wound and/or area of interestin degrees Celsius or degrees Fahrenheit; the percent of pixels thatfall within a particular pre-determined range of the unaffectedreference area; the minimum temperature compared to an unaffectedreference point; the maximum temperature compared to an unaffectedreference point; or a mean temperature compared to an unaffectedreference point.

Baseline Reference Area User Requirements

User must set head direction on the visual image (can be obtained fromeither current L×W function or the addition of a Set Head Direction onlyfunction)

User must either overlay an External Wound Trace and place it ontothermal image or perform a Thermal Wound Trace on the thermal image

A manual Reference Area must be selected using the current functionality

Baseline Database Requirements

-   -   Angle formed from the selected head direction relative to the        center point of the overlaid External Wound Trace or Freeform        Wound Trace from thermal image and the manually selected        Reference Area    -   Distance from the center point of the External Wound Trace or        Freeform Wound Trace to the manually selected Reference Area

Automated Reference Area User Requirements

User must set head direction on the visual image (can be obtained fromeither current L×W function or the addition of a Set Head Direction onlyfunction)

User must either overlay an External Wound Trace and place it ontothermal image or perform a Thermal Wound Trace on the thermal image

User must click the Automate Reference Area button

User must either confirm they agree with automated placement or disagreeand place it manually.

Automated Reference Area Database Requirements

Recall of angle formed from the selected head direction relative to thecenter point of the overlaid External Wound Trace or Freeform WoundTrace from thermal image and the manually selected Reference Area fromthe most recent session with a manually selected Reference Area

Recall distance from the center point of the External Wound Trace orFreeform Wound Trace from the most recent session with a manuallyselected Reference Area

Based upon the user's current selection of head direction and the centerpoint of the overlaid External Wound Trace or Freeform Wound Trace fromthermal image, an approximation of the location of prior Reference Areascan be determined

MISCELLANEOUS

User disagrees with Reference Area Automation and manually selects a newarea; this manual selection now becomes the baseline

User does not have to user Automated Reference Area; a user could do themanual selection every time.

APPENDIX 1

If selecting unaffected reference point:

1. Check whether thermal trace exists2. If yes, check to see which pixels fall inside the trace and use thepixel values of all those pixels to calculate the average pixel value(mean). If not stop3. Decide on the color codes that represent each temperature intervalchange. 15 different shades were chosen for the color scale. Gray scalecolors are used before the reference point is selected.4. Use the base color that falls in the middle of the color scale tohighlight all the pixels with a pixel value between mean−6 and mean+6.The following logic was used to color rest of the pixels5.

if(PV <(Mean− 6− (6 ″′PI))) { Highlight the pixels using the color′thatfalls in the bottom of the scale representing the coldest pixels } elseif (PV >=(Mean − 6 − (6 *PI)) & PV <(Mean− 6 − (5 *PI))) { Highlight thepixels using the color that is second from the bottom of the scale }else if (PV >=(Mean − 6 − (5 * PI)) & PV <(Mean− 6 − ( 4 * PI))) {Highlight the pixels using the color that is third from the bottom ofthe scale } else if (PV >=(Mean − 6 − ( 4 *PI)) & PV <(Mean − 6 − (3 *Pl))) { 3 Highlight the pixels using the color that is fourth from thebottom of the scale } else if (PV >= (Mean − 6− (3 *PI)) & PV <(Mean −6− (2 *PI))) { Highlight the pixels using the color that is fifth fromthe bottom of the scale } else if (PV >= (Mean − 6 − (2 *PI)) & PV <(Mean −6 − (1 *PI))) { Highlight the pixels using the color that issixth from the bottom of the scale } else if(PV >=(Mean − 6− (1 *PI)) &PV <(Mean − 6)) { Highlight the pixels using the color that is seventhfrom the bottom of the scale } else ir(PV >= (Mean − 6) & PV <=(Mean +6)) { Highlight the pixels using the base color representing unaffectedarea. (Center color) } else if(PV >(Mean + 6) & PV <=(Mean + 6 + (1 *PI))) { Highlight the pixels using the coJor that is seventh from thetop of the scale } else if(PV >(Mean + 6 + (1 *PI)) & PV <= (Mean + 6 +(2 * PI))) { Highlight the pixels using the color that is sixth from thetop of the scale } else if(PV > (Mean + 6 + (2 * PI)) & PV <=(Mean + 6 +(3 *PI))) { Highlight the pixels using the color that is fifth from thetop of the scale } else if (PV >(Mean + 6 + (3 * PI)) & PV <= (Mean +6 + ( 4 *PI))) { Highlight the pixels using the color that is fourthfrom the top of the scale } else if (PV >(Mean + 6 + (4 *PI)) & PV<=(Mean + 6 + (5 * PI))) { Highlight the pixels using the color that isthird from the top of the scale } else if (PV >(Mean + 6 + (5 *PI)) & PV<=(Mean + 6 + (6 *PI))) { Highlight the pixels using the color that issecond from the top of the scale } else if (PV >(Mean + 6 + (6 * PI))) {Highlight the pixels using the color that falls in the top of the scalerepresenting the hottest pixels } Where PV − Pixel Value and PI = pixelincrement. PI is set to 13 when the mosaic needs to show 1°C change intemperature, PI is set to 9 for 0.75°C and 6 for 0.5°C change intemperature.

APPENDIX 2

The ‘lensdistort’ algorithm in Matlab takes as input the originaldistorted image and the following parameters and generates as output thebarrel distortion corrected image.

‘bordertype’—String that controls the treatment of the image edges.Valid strings are ‘fit’ and ‘crop’. By default, ‘bordertype’ is set to‘crop’.‘interpolation’-String that specifies the interpolating kernel that theseparable re-sampler uses. Valid strings are ‘cubic’, ‘linear’ and‘nearest’. By default, the ‘interpolation’ is set to ‘cubic’‘padmethod’—String that controls how the re-sampler interpolates orassigns values to output elements that map close to or outside the edgeof the input array. Valid strings are ‘bound’, circular′, ‘replicate’,and symmetric′. By default, the ‘padmethod’ is set to ‘fill’‘ftype’—Integer between 1 and 4 that specifies the distortion model tobe used. The models available are1. ‘ftype’=1: s=r.*(1./(1+k.*r));2. ‘ftype’=2: s=r.*(1./(1+k.*(r/'2)));3. ‘ftype’=3: s=r.*(1+k.*r);4. ‘ftype’=4: s=r.*(1+k.*(r.A2));By default, the ‘ftype’ is set to 4.

APPENDIX 3

In order to generate the color mosaic the mean (average) pixel value ofthe unaffected reference point would be used as the ‘Mean’ in thealgorithm described above for generating thermal mosaic. Since referencepoint is just one pixel there is only one pixel value. If that pixelvalue is used as the mean it introduces a lot of variation in theresults. Every time a different reference point is selected, even thoughvery close to the previously selected location the results varied a lotand were not repeatable so instead the following method was used

1. Calculate the difference between the selected reference point pixelvalue and mean pixel value of the thermal trace (the value that was usedfor generating the gray scale thermal mosaic)2.

${increment} = \frac{{Difference}\mspace{14mu} {calculated}\mspace{14mu} {from}\mspace{14mu} {step}\mspace{11mu} 1}{{Pixel}\mspace{14mu} {Increment}}$

Pixel Increment is set to 13 when the mosaic needs to show 1° C. changein temperature, 9 for 0.75° C. and 6 for 0.5° C. change in temperature3.

 if (increment>O) { Reference_min =(mean + 6 +((increment − 1) *PixelIncrement)) + 1; Reference_max= (mean+ 6 + ((increment) *PixelIncrement)); } else if (increment= 0) { Reference_min= (mean− 6);Reference_max= (mean + 6); } else if (increment< 0) { Reference_min=(mean− 6 +((increment) *Pixel Increment)); Reference_max= (mean− 6+((increment+ I) *Pixel Increment)) −1; } where mean= mean pixel valueof the thermal trace;4. Mean (average) pixel value of the unaffected reference point can thenbe calculated as Reference_mean=(Reference_min+Reference_max)/2Reference_mean as calculated above can then be used as the ‘Mean’ in thealgorithm described earlier for generating thermal mosaic. Use RGB colorcodes to generate Color mosaic.

1. A system for determining a clinically relevant temperaturedifferential between a predetermined area of interest on the bodysurface of a mammal and a control area on the body surface of saidmammal, said system comprising: a visual and thermal image capturingdevice, said image capturing device comprising: a housing, a means forcapturing a digital visual image within said housing; and a means forcapturing a digital thermal image within said housing; a displayapparatus, said display apparatus comprising means for showing saidcaptured visual image and said captured thermal image; and a computingapparatus, said computing apparatus operatively connected to said imagecapturing device and to said display apparatus, said computing apparatuscomprising: a means for selecting a control area on the surface of thebody; a means for determining a temperature of said control area; ameans for overlaying said digital image onto said thermal image in adesired orientation on said display apparatus; and a means for applyinga unique pixel value to a specific predetermined temperature range onsaid thermal image.
 2. The system of claim 1, wherein the system furthercomprises a means for selecting an area of clinical interest within saidvisual image.
 3. The system of claim 1, wherein the system furthercomprises a means for calculating plane geometric features of saidselected area of clinical interest.
 4. The system of claim 1, whereinthe system further comprises a means for overlaying said digital imageonto said thermal image in a desired orientation on said displayapparatus.
 5. A system for determining a clinically relevant temperaturedifferential between a predetermined area of interest on the bodysurface of a mammal and a control area on the body surface of saidmammal, said system comprising: a visual and thermal image capturingdevice, said image capturing device comprising: a housing, a means forcapturing a digital visual image within said housing; and a means forcapturing a digital thermal image within said housing; a displayapparatus, said display apparatus comprising means for showing saidcaptured visual image and said captured thermal image; and a computingapparatus, said computing apparatus operatively connected to said imagecapturing device and to said display apparatus, said computing apparatuscomprising: a means for selecting a control area on the surface of thebody; a means for determining a temperature of said control area; ameans for selecting an area of clinical interest within said visualimage; a means for calculating plane geometric features of said selectedarea of clinical interest; a means for overlaying said digital imageonto said thermal image in a desired orientation on said displayapparatus; and a means for applying a unique pixel value to a specificpredetermined temperature range on said thermal image.
 6. A method ofcontemporaneously comparing an average temperature of predetermined areaof interest on the body surface of a mammal and a control area on thebody surface of said mammal, said method comprising the steps of:capturing a physical image of a portion of the body of a mammal;capturing a thermal image of said body portion; displaying said physicaland said thermal image on a screen; selecting a control area on thesurface of the skin; determining an temperature of said control area;selecting an area of clinical interest within said visual image;calculating plane geometric features of said selected area of clinicalinterest; overlaying said digital image onto said thermal image in adesired orientation on said display apparatus; and applying a uniquepixel value to a specific predetermined temperature range on saidthermal image.
 7. The method of claim 6, wherein the method furthercomprise selecting an area of clinical interest within said visualimage.
 8. The method of claim 6, wherein the method further comprisecalculating plane geometric features of said selected area of clinicalinterest.
 9. The method of claim 6, wherein the method further compriseoverlaying said digital image onto said thermal image in a desiredorientation on said display apparatus
 10. A method of contemporaneouslycomparing an average temperature of predetermined area of interest onthe body surface of a mammal and a control area on the body surface ofsaid mammal, said method comprising the steps of: capturing a physicalimage of a portion of the body of a mammal; capturing a thermal image ofsaid body portion; displaying said physical and said thermal image on ascreen; selecting a control area on the surface of the body; determiningan temperature of said control area; selecting an area of clinicalinterest within said visual image; calculating plane geometric featuresof said selected area of clinical interest; overlaying said digitalimage onto said thermal image in a desired orientation on said displayapparatus; and applying a unique pixel value to a specific predeterminedtemperature range on said thermal image.